Add a dhrystone benchmark command

Drystone provides a convenient sanity check that the CPU is running at full
speed. Add this as a command which can be enabled as needed.

Note: I investigated using Coremark for this but there was a license
agreement and I could not work out if it was GPL-compatible.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/dhry/dhry.h b/lib/dhry/dhry.h
new file mode 100644
index 0000000..49d4223
--- /dev/null
+++ b/lib/dhry/dhry.h
@@ -0,0 +1,442 @@
+/*
+ * (C) Copyright 2015 Google, Inc
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ *
+ * Dhrystone is widely available in the public domain. A GPL license is
+ * chosen for U-Boot.
+ */
+
+/*****************************************************************************
+ *  The BYTE UNIX Benchmarks - Release 3
+ *          Module: dhry.h   SID: 3.4 5/15/91 19:30:21
+ *          
+ *****************************************************************************
+ * Bug reports, patches, comments, suggestions should be sent to:
+ *
+ *	Ben Smith, Rick Grehan or Tom Yager
+ *	ben@bytepb.byte.com   rick_g@bytepb.byte.com   tyager@bytepb.byte.com
+ *
+ *****************************************************************************
+ *  Modification Log:
+ *  addapted from:
+ *
+ *
+ *                   "DHRYSTONE" Benchmark Program
+ *                   -----------------------------
+ *                                                                            
+ *  Version:    C, Version 2.1
+ *                                                                            
+ *  File:       dhry.h (part 1 of 3)
+ *
+ *  Date:       May 25, 1988
+ *
+ *  Author:     Reinhold P. Weicker
+ *                      Siemens AG, AUT E 51
+ *                      Postfach 3220
+ *                      8520 Erlangen
+ *                      Germany (West)
+ *                              Phone:  [+49]-9131-7-20330
+ *                                      (8-17 Central European Time)
+ *                              Usenet: ..!mcvax!unido!estevax!weicker
+ *
+ *              Original Version (in Ada) published in
+ *              "Communications of the ACM" vol. 27., no. 10 (Oct. 1984),
+ *              pp. 1013 - 1030, together with the statistics
+ *              on which the distribution of statements etc. is based.
+ *
+ *              In this C version, the following C library functions are used:
+ *              - strcpy, strcmp (inside the measurement loop)
+ *              - printf, scanf (outside the measurement loop)
+ *              In addition, Berkeley UNIX system calls "times ()" or "time ()"
+ *              are used for execution time measurement. For measurements
+ *              on other systems, these calls have to be changed.
+ *
+ *  Collection of Results:
+ *              Reinhold Weicker (address see above) and
+ *              
+ *              Rick Richardson
+ *              PC Research. Inc.
+ *              94 Apple Orchard Drive
+ *              Tinton Falls, NJ 07724
+ *                      Phone:  (201) 834-1378 (9-17 EST)               
+ *                      Usenet: ...!seismo!uunet!pcrat!rick
+ *
+ *      Please send results to Rick Richardson and/or Reinhold Weicker.
+ *      Complete information should be given on hardware and software used.
+ *      Hardware information includes: Machine type, CPU, type and size
+ *      of caches; for microprocessors: clock frequency, memory speed
+ *      (number of wait states).
+ *      Software information includes: Compiler (and runtime library)
+ *      manufacturer and version, compilation switches, OS version.
+ *      The Operating System version may give an indication about the
+ *      compiler; Dhrystone itself performs no OS calls in the measurement loop.
+ *
+ *      The complete output generated by the program should be mailed
+ *      such that at least some checks for correctness can be made.
+ *
+ ***************************************************************************
+ *
+ *  History:    This version C/2.1 has been made for two reasons:
+ *
+ *              1) There is an obvious need for a common C version of
+ *              Dhrystone, since C is at present the most popular system
+ *              programming language for the class of processors
+ *              (microcomputers, minicomputers) where Dhrystone is used most.
+ *              There should be, as far as possible, only one C version of
+ *              Dhrystone such that results can be compared without
+ *              restrictions. In the past, the C versions distributed
+ *              by Rick Richardson (Version 1.1) and by Reinhold Weicker
+ *              had small (though not significant) differences.
+ *
+ *              2) As far as it is possible without changes to the Dhrystone
+ *              statistics, optimizing compilers should be prevented from
+ *              removing significant statements.
+ *
+ *              This C version has been developed in cooperation with
+ *              Rick Richardson (Tinton Falls, NJ), it incorporates many
+ *              ideas from the "Version 1.1" distributed previously by
+ *              him over the UNIX network Usenet.
+ *              I also thank Chaim Benedelac (National Semiconductor),
+ *              David Ditzel (SUN), Earl Killian and John Mashey (MIPS),
+ *              Alan Smith and Rafael Saavedra-Barrera (UC at Berkeley)
+ *              for their help with comments on earlier versions of the
+ *              benchmark.
+ *
+ *  Changes:    In the initialization part, this version follows mostly
+ *              Rick Richardson's version distributed via Usenet, not the
+ *              version distributed earlier via floppy disk by Reinhold Weicker.
+ *              As a concession to older compilers, names have been made
+ *              unique within the first 8 characters.
+ *              Inside the measurement loop, this version follows the
+ *              version previously distributed by Reinhold Weicker.
+ *
+ *              At several places in the benchmark, code has been added,
+ *              but within the measurement loop only in branches that 
+ *              are not executed. The intention is that optimizing compilers
+ *              should be prevented from moving code out of the measurement
+ *              loop, or from removing code altogether. Since the statements
+ *              that are executed within the measurement loop have NOT been
+ *              changed, the numbers defining the "Dhrystone distribution"
+ *              (distribution of statements, operand types and locality)
+ *              still hold. Except for sophisticated optimizing compilers,
+ *              execution times for this version should be the same as
+ *              for previous versions.
+ *              
+ *              Since it has proven difficult to subtract the time for the
+ *              measurement loop overhead in a correct way, the loop check
+ *              has been made a part of the benchmark. This does have
+ *              an impact - though a very minor one - on the distribution
+ *              statistics which have been updated for this version.
+ *
+ *              All changes within the measurement loop are described
+ *              and discussed in the companion paper "Rationale for
+ *              Dhrystone version 2".
+ *
+ *              Because of the self-imposed limitation that the order and
+ *              distribution of the executed statements should not be
+ *              changed, there are still cases where optimizing compilers
+ *              may not generate code for some statements. To a certain
+ *              degree, this is unavoidable for small synthetic benchmarks.
+ *              Users of the benchmark are advised to check code listings
+ *              whether code is generated for all statements of Dhrystone.
+ *
+ *              Version 2.1 is identical to version 2.0 distributed via
+ *              the UNIX network Usenet in March 1988 except that it corrects
+ *              some minor deficiencies that were found by users of version 2.0.
+ *              The only change within the measurement loop is that a
+ *              non-executed "else" part was added to the "if" statement in
+ *              Func_3, and a non-executed "else" part removed from Proc_3.
+ *
+ ***************************************************************************
+ *
+ * Defines:     The following "Defines" are possible:
+ *              -DREG=register          (default: Not defined)
+ *                      As an approximation to what an average C programmer
+ *                      might do, the "register" storage class is applied
+ *                      (if enabled by -DREG=register)
+ *                      - for local variables, if they are used (dynamically)
+ *                        five or more times
+ *                      - for parameters if they are used (dynamically)
+ *                        six or more times
+ *                      Note that an optimal "register" strategy is
+ *                      compiler-dependent, and that "register" declarations
+ *                      do not necessarily lead to faster execution.
+ *              -DNOSTRUCTASSIGN        (default: Not defined)
+ *                      Define if the C compiler does not support
+ *                      assignment of structures.
+ *              -DNOENUMS               (default: Not defined)
+ *                      Define if the C compiler does not support
+ *                      enumeration types.
+ *              -DTIMES                 (default)
+ *              -DTIME
+ *                      The "times" function of UNIX (returning process times)
+ *                      or the "time" function (returning wallclock time)
+ *                      is used for measurement. 
+ *                      For single user machines, "time ()" is adequate. For
+ *                      multi-user machines where you cannot get single-user
+ *                      access, use the "times ()" function. If you have
+ *                      neither, use a stopwatch in the dead of night.
+ *                      "printf"s are provided marking the points "Start Timer"
+ *                      and "Stop Timer". DO NOT use the UNIX "time(1)"
+ *                      command, as this will measure the total time to
+ *                      run this program, which will (erroneously) include
+ *                      the time to allocate storage (malloc) and to perform
+ *                      the initialization.
+ *              -DHZ=nnn
+ *                      In Berkeley UNIX, the function "times" returns process
+ *                      time in 1/HZ seconds, with HZ = 60 for most systems.
+ *                      CHECK YOUR SYSTEM DESCRIPTION BEFORE YOU JUST APPLY
+ *                      A VALUE.
+ *
+ ***************************************************************************
+ *
+ *  Compilation model and measurement (IMPORTANT):
+ *
+ *  This C version of Dhrystone consists of three files:
+ *  - dhry.h (this file, containing global definitions and comments)
+ *  - dhry_1.c (containing the code corresponding to Ada package Pack_1)
+ *  - dhry_2.c (containing the code corresponding to Ada package Pack_2)
+ *
+ *  The following "ground rules" apply for measurements:
+ *  - Separate compilation
+ *  - No procedure merging
+ *  - Otherwise, compiler optimizations are allowed but should be indicated
+ *  - Default results are those without register declarations
+ *  See the companion paper "Rationale for Dhrystone Version 2" for a more
+ *  detailed discussion of these ground rules.
+ *
+ *  For 16-Bit processors (e.g. 80186, 80286), times for all compilation
+ *  models ("small", "medium", "large" etc.) should be given if possible,
+ *  together with a definition of these models for the compiler system used.
+ *
+ **************************************************************************
+ *
+ *  Dhrystone (C version) statistics:
+ *
+ *  [Comment from the first distribution, updated for version 2.
+ *   Note that because of language differences, the numbers are slightly
+ *   different from the Ada version.]
+ *
+ *  The following program contains statements of a high level programming
+ *  language (here: C) in a distribution considered representative:           
+ *
+ *    assignments                  52 (51.0 %)
+ *    control statements           33 (32.4 %)
+ *    procedure, function calls    17 (16.7 %)
+ *
+ *  103 statements are dynamically executed. The program is balanced with
+ *  respect to the three aspects:                                             
+ *
+ *    - statement type
+ *    - operand type
+ *    - operand locality
+ *         operand global, local, parameter, or constant.                     
+ *
+ *  The combination of these three aspects is balanced only approximately.    
+ *
+ *  1. Statement Type:                                                        
+ *  -----------------             number
+ *
+ *     V1 = V2                     9
+ *       (incl. V1 = F(..)
+ *     V = Constant               12
+ *     Assignment,                 7
+ *       with array element
+ *     Assignment,                 6
+ *       with record component
+ *                                --
+ *                                34       34
+ *
+ *     X = Y +|-|"&&"|"|" Z        5
+ *     X = Y +|-|"==" Constant     6
+ *     X = X +|- 1                 3
+ *     X = Y *|/ Z                 2
+ *     X = Expression,             1
+ *           two operators
+ *     X = Expression,             1
+ *           three operators
+ *                                --
+ *                                18       18
+ *
+ *     if ....                    14
+ *       with "else"      7
+ *       without "else"   7
+ *           executed        3
+ *           not executed    4
+ *     for ...                     7  |  counted every time
+ *     while ...                   4  |  the loop condition
+ *     do ... while                1  |  is evaluated
+ *     switch ...                  1
+ *     break                       1
+ *     declaration with            1
+ *       initialization
+ *                                --
+ *                                34       34
+ *
+ *     P (...)  procedure call    11
+ *       user procedure      10
+ *       library procedure    1
+ *     X = F (...)
+ *             function  call      6
+ *       user function        5                                         
+ *       library function     1                                               
+ *                                --                                          
+ *                                17       17
+ *                                        ---
+ *                                        103
+ *
+ *    The average number of parameters in procedure or function calls
+ *    is 1.82 (not counting the function values as implicit parameters).
+ *
+ *
+ *  2. Operators
+ *  ------------
+ *                          number    approximate
+ *                                    percentage
+ *
+ *    Arithmetic             32          50.8                                 
+ *
+ *       +                     21          33.3                              
+ *       -                      7          11.1                              
+ *       *                      3           4.8
+ *       / (int div)            1           1.6
+ *
+ *    Comparison             27           42.8
+ *
+ *       ==                     9           14.3
+ *       /=                     4            6.3
+ *       >                      1            1.6
+ *       <                      3            4.8
+ *       >=                     1            1.6
+ *       <=                     9           14.3
+ *
+ *    Logic                   4            6.3
+ *
+ *       && (AND-THEN)          1            1.6
+ *       |  (OR)                1            1.6
+ *       !  (NOT)               2            3.2
+ * 
+ *                           --          -----
+ *                           63          100.1
+ *
+ *
+ *  3. Operand Type (counted once per operand reference):
+ *  ---------------
+ *                          number    approximate
+ *                                    percentage
+ *
+ *     Integer               175        72.3 %
+ *     Character              45        18.6 %
+ *     Pointer                12         5.0 %
+ *     String30                6         2.5 %
+ *     Array                   2         0.8 %
+ *     Record                  2         0.8 %
+ *                           ---       -------
+ *                           242       100.0 %
+ *
+ *  When there is an access path leading to the final operand (e.g. a record
+ *  component), only the final data type on the access path is counted.       
+ *
+ *
+ *  4. Operand Locality:                                                      
+ *  -------------------
+ *                                number    approximate
+ *                                          percentage
+ *
+ *     local variable              114        47.1 %
+ *     global variable              22         9.1 %
+ *     parameter                    45        18.6 %
+ *        value                        23         9.5 %
+ *        reference                    22         9.1 %
+ *     function result               6         2.5 %
+ *     constant                     55        22.7 %
+ *                                 ---       -------
+ *                                 242       100.0 %
+ *
+ *
+ *  The program does not compute anything meaningful, but it is syntactically
+ *  and semantically correct. All variables have a value assigned to them
+ *  before they are used as a source operand.
+ *
+ *  There has been no explicit effort to account for the effects of a
+ *  cache, or to balance the use of long or short displacements for code or
+ *  data.
+ *
+ ***************************************************************************
+ */
+
+
+/* Compiler and system dependent definitions: */
+
+#ifndef TIME
+#define TIMES
+#endif
+                /* Use times(2) time function unless    */
+                /* explicitly defined otherwise         */
+
+#define Mic_secs_Per_Second     1000000.0
+                /* Berkeley UNIX C returns process times in seconds/HZ */
+
+#ifdef  NOSTRUCTASSIGN
+#define structassign(d, s)      memcpy(&(d), &(s), sizeof(d))
+#else
+#define structassign(d, s)      d = s
+#endif
+
+#ifdef  NOENUM
+#define Ident_1 0
+#define Ident_2 1
+#define Ident_3 2
+#define Ident_4 3
+#define Ident_5 4
+  typedef int   Enumeration;
+#else
+  typedef       enum    {Ident_1, Ident_2, Ident_3, Ident_4, Ident_5}
+                Enumeration;
+#endif
+        /* for boolean and enumeration types in Ada, Pascal */
+
+/* General definitions: */
+
+#define Null 0 
+                /* Value of a Null pointer */
+#define true  1
+#define false 0
+
+typedef int     One_Thirty;
+typedef int     One_Fifty;
+typedef char    Capital_Letter;
+typedef int     Boolean;
+typedef char    Str_30 [31];
+typedef int     Arr_1_Dim [50];
+typedef int     Arr_2_Dim [50] [50];
+
+typedef struct record 
+    {
+    struct record *Ptr_Comp;
+    Enumeration    Discr;
+    union {
+          struct {
+                  Enumeration Enum_Comp;
+                  int         Int_Comp;
+                  char        Str_Comp [31];
+                  } var_1;
+          struct {
+                  Enumeration E_Comp_2;
+                  char        Str_2_Comp [31];
+                  } var_2;
+          struct {
+                  char        Ch_1_Comp;
+                  char        Ch_2_Comp;
+                  } var_3;
+          } variant;
+      } Rec_Type, *Rec_Pointer;
+
+
+/*
+ * dhry() - run dhrystone for a given number of iterations
+ *
+ * @iterations:	Number of iterations to run
+ */
+void dhry(int iterations);